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Observación de los estados de Floquet-Bloch en la superficie de un aislante topológico
Y H Wang1, H Steinberg, P Jarillo-Herrero
1Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Science (New York, N.Y.)
|October 26, 2013
Resumen
La luz intensa crea estados cuánticos exóticos en las superficies de aislantes topológicos. Este estudio revela cómo la luz circularmente polarizada rompe la simetría de la inversión del tiempo, abriendo puertas para el control óptico de materiales cuánticos.
Área de la Ciencia:
- Física de la materia condensada Física de la materia condensada
- Ciencia de los materiales cuánticos Ciencia de los materiales cuánticos.
- La fotónica es la fotónica.
Sus antecedentes:
- Los aislantes topológicos poseen propiedades únicas de electrones de superficie protegidos por la simetría de inversión del tiempo.
- La ruptura de la simetría de inversión del tiempo podría inducir fenómenos cuánticos exóticos, como un estado Hall cuántico de superficie.
Objetivo del estudio:
- Para investigar la interacción entre la luz ultracorta intensa de infrarrojo medio y los estados de superficie del aislante topológico.
- Explorar la formación de las bandas de Floquet-Bloch y su respuesta a la polarización de la luz.
Principales métodos:
- Se utilizó la espectroscopia de fotoemisión con resolución de tiempo y ángulo (TARPS).
- Empleó intensos pulsos láser ultracortos de infrarrojo medio con energía por debajo de la brecha de la banda principal.
Principales resultados:
- Se observó la hibridación del pulso de luz con fermiones Dirac superficiales, formando bandas de Floquet-Bloch.
- Se han demostrado brechas de banda dependientes de la polarización en los cruces evitados en las bandas vestidas con fotones.
- Mostró que los fotones polarizados circularmente inducen una brecha de banda en el punto de Dirac, lo que indica una simetría de inversión de tiempo rota.
Conclusiones:
- Estableció la existencia y las propiedades de las bandas de Floquet-Bloch en aislantes topológicos.
- Abrió el camino para la manipulación óptica de los estados cuánticos topológicos utilizando la polarización de la luz.
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